Osisko Mining Corporation: Document Search at Canadian Malartic

MALARTIC, QUEBEC--(Marketwire - Nov. 28, 2012) - Osisko Mining Corporation ("Osisko" or the "Corporation")(TSX:OSK)(FRANKFURT:EWX) reports that, this morning, representatives of the ministère du Développement durable, de l'Environnement, de la Faune et des Parcs du Québec ("MDDEFP") entered the site of its Canadian Malartic mine to conduct a search. Representatives of the MDDEFP requested and obtained documents relating to drilling, loading and blasting activities for certain dates between April 2011 and October 2012.

Osisko is cooperating fully with the authorities and with the ongoing investigation. The Corporation believes that its operations are in compliance with laws and regulations, particularly with regard to environmental protection.

Mining operations are continuing on a normal basis.

About Osisko Mining Corporation

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Quebec and is pursuing exploration activities on various properties, including the Hammond Reef Gold Project in Northern Ontario.

The Company is listed on the Toronto Stock Exchange (TSX:OSK) in Canada and the Deutsche Boerse (FRANKFURT:EWX) in Germany.

Forward-Looking Statements

Certain statements contained in this press release may be deemed "forward-looking statements". All statements in this release, other than statements of historical fact, that address events or developments that Osisko expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects", "plans", "anticipates", "believes", "intends", "estimates", "projects", "potential", "scheduled" and similar expressions, or that events or conditions "will", "would", "may", "could" or "should" occur including, without limitation, outcome of the investigation conducted by the MDDEFP. Although Osisko believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation, that all technical, economical and financial conditions will be met in order to achieve such events qualified by the foregoing cautionary note regarding forward looking statements, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, access to skilled consultants, mining development and construction personnel, results of exploration and development activities, Osisko's limited experience with production and mining operations, uninsured risks, regulatory framework and changes, defects in title, availability of personnel, materials and equipment, timeliness of government approvals, actual performance of facilities, equipment and processes relative to specifications and expectations, unanticipated environmental impacts on operations market prices, continued availability of capital and financing and general economic, market or business conditions. These factors are discussed in greater detail in Osisko's most recent Annual Information Form and in the most recent Management Discussion and Analysis filed on SEDAR, which also provide additional general assumptions in connection with these statements. Osisko cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. Osisko believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.